Therapeutic challenges in pediatric dermatology

June 1, 2007

Novel therapeutic options for warts or atopic dermatitis include immunotherapy for the former, and cyclosporine and recombinant interferon gamma for the latter.

Key Points

When the gamut of standard therapies fails, frustration may set in for both patient and physician. One expert has offered some novel treatment options for these potentially difficult-to-treat diseases.

Verrucae vulgaris

"Yet some patients do not react to these standard therapies. To get rid of hard-to-treat warts, immunotherapy in the form of intralesional injection of skin test antigens and topical contact sensitizers has been shown to work fairly well," says Richard J. Antaya, M.D., associate professor of dermatology and pediatrics, Yale University School of Medicine, New Haven, Conn.

The exact mechanism of immunotherapy for warts is unknown, but several successful trials support its use as an alternative therapeutic option. It is less painful than destructive modalities, relatively inexpensive, leaves minimal-to-no scarring, and yields low recurrence rates.

Dr. Antaya cites a study in which 149 patients with longstanding warts, recalcitrant to standard therapies, were treated with Candida antigen injection. Treatment consisted of 0.1 ml of 1:1 Candin:1 percent lidocaine into each wart (up to 1 ml total) every four weeks. Results showed a complete cure within eight weeks of the last injection without recurrence in 72 percent of the patients. Only minor local reaction was reported; no serious complications occurred.

Similar trials using this intralesional immunotherapy approach have been done with mumps, Candida and Trichophyton skin test antigens and have shown around 50 percent to 80 percent wart clearance, including untreated warts at distant sites. Treatment protocol consists of the injection of 0.1 ml of Candida (1:1,000) +/- T. Mentagrophytes antigen below the wart, every three to four weeks, usually with a maximum of four to five treatments.

"The response does not appear to be related to MHC or viral type, and older subjects seem less likely to respond. Immunotherapy with skin test antigens does not represent a direct vaccination, but evidence suggests that the patient's immune system does not become stimulated against wart virus," Dr. Antaya says.

Another approach in the treatment of warts with immunotherapy is the topical application of 2 percent squaric acid dibutylester (SADBE). One study that included 148 patients showed a complete clinical resolution in 124 patients (84 percent). In 101 patients, a two-year follow-up showed no relapses, and no significant side effects were reported. Indications for this therapy are resistant, multiple, non-facial verruca vulgares or refusal of alternative treatments.

"Immunotherapy for warts in children is safe, efficacious and relatively well-tolerated, as well as cost-effective. Yet further studies are needed to firmly establish this therapeutic modality," Dr. Antaya tells Dermatology Times.

Atopic dermatitis

Dr. Antaya says children with recalcitrant atopic dermatitis can be difficult to treat.

Optional treatment approaches for difficult-to-treat cases that achieve positive results can include cyclosporine and recombinant interferon gamma.

When using cyclosporine, Dr. Antaya follows a three-stage treatment regimen. In stage one, a rapid improvement of symptoms can be seen. This stage consists of approximately a two-month therapy of 5 mg/kg/day divided into two daily doses. Stage two includes a dose reduction; the daily dose is decreased by 1 mg/kg/day in stages.

Stage three is the tapering stage and usually should not exceed six months. Dr. Antaya says cyclosporine should only be used in severe atopic dermatitis nonresponsive to standard therapies, and can be used as an adjunctive to topical immunomodulators.

"Studies show cyclosporine to be efficacious in a majority of patients who are recalcitrant to standard therapies. The long-term risk of lymphoma appears to be very low, and there is no rebound phenomenon with cessation of the drug. Also, a long-term remission of atopic dermatitis is seen in about 10 percent of patients, even with short, six-week courses," Dr. Antaya says.

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